Metallurgy of ores of zinc, &amp;c.



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PATENTED PEB. 1.8, 1908.

F. MEYER. METALLURGY 0F ORES 0F ZINC, Guo,

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AIPLIOATION FILED JANJS, 1906.

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APPLIOATION FILED .TA-NJB, 19406.

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MBTALLUR v UNiTED srarns` PATENT OFFICE;

FRANZ MEYER, OF ENGLEWOOD, NEW JERSEY, ASSIGNOR TO METALLURGIOAL COMPANY OF AMERICA, OF NEW YORK, N. Y., A CORPORATION OF NEW `TERSEY.

METALLURGY OF GRES OF ZINC, &c.

Specification of Letters Patent.

Patented Feb. 18, 1908.

Application filed January 13| 1906. Serial No. 295.928.

To all whom it may concern:

Be it known that I, FRANZ MEYER, a subject of the Emperor of Germany, residing at Englewood, county of Bergen, State of New Jersey, and whose post-oflice address is No. 52 Broadway, city, county, and State of New York, have invented certain new and useful Imfprovements in Metallurgy of O'res of Zinc an the Like, and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to the metallurgy of ores and other material containing metal, and has for its object a continuous process, consisting broadly stated, in feeding the furnace charge, in an upward direction, within an internally heated chamber, so as to constantly renew the material supplied to the active zone or zones of the furnace, 'and so as to continuously dischar e the spent ore or ash by the lifting effect of the upwardly moving ortions below, thereby maintaining practica ly uniform conditions in the furnace during its continuous and progressive operation.

The invention is especially'applicable to the recovery of such metals as are volatile at the temperature at which they are reduced from their ores, as, for instance, Zinc.

Other features of the invention consist in inducing a down-draft in the main stack during the upward movement of the charge; recuperating the waste heat of the spent charge or ash, by passing the incoming air or gas, or both, through the ash, varying or controlling the conditions prevailing within the .main stack by the further supply of fuel thereto in the form of solid, liquid or gaseous fuel, su plied at the place where the ash is diverte from the charge, or (when gaseous) preferably from a special producer stack arranged adjacent to the main stack; and condensing out th'e volatilized metallfrom the gaseous products of combustion and reaction as they issue from the main stack and maintaining the condensed metal' in a liquid condition, so as to permit it to be readily drawn off at suitable intervals.

In an application of even date herewith Serial No. 295,929 I have described and shown various forms of apparatus for carrying out these several operations. The presen't application concerns the method or methods employed for attaining the results contemplated, and may be carried out in any of the several furnaces shown in my said co-pending application.

1n the accompanying drawings, Figure l represents an elevation of a furnace suitable for the practice of my invention 5 Fig. 2 represents a vertical sectional view on the line 2 2 of Fig. 3; Fig. 3 represents a vertical sectional View on the line 3-3 of Fig. 2, Fig. 4l represents a horizontal section, on the line4-4 of Fig. 3.

Similar letters of reference indicate similar parts throughout the several views.

Referring to the drawings, A indicates the main stack, for the reception of the mixture of ore or like metal-bearing material containing the metal to be reduced or volatilized in the furnace, together with the fuel, fluxes or similar ingredients desirable for the particular metallurgical operation at hand. This mixture is supplied by the hopper B to a horizontal conveyer, which may conveniently consist of a feed screw a, operating in the conduit C, which latter communicates with the lower portion of the stack. In many cases, also, it will be desirable to supplement the horizontally acting screw a, with a vertically acting screw b, as shown, in order to diminish any tendency to clogging.

The main stack A is se arated by a partition wall c from an auxi iary stack or compartment D, which receives the ash or spent ore from the main stack, and a door d serves as a convenient means forremoving the ash or a portion thereof, from time to time. At the base of the ash stack is located the air-admission pipe e, having theprojecting cap f, andwhich also contains a pipe s for the admission of gas, if desired, for-changing the character or intensity of the re-actions going on in the main stack. So also, inlet ports m, permit the addition of fuel (solid, liquid or gaseous), fluxing material, or other re-agent appropriate to the treatment of the furnace charge. These ports m may also serve for the insertion of suitable stoking tools for working or stirring the charge in the main stack or the cinders in the ash stack, to break up or prevent any crusts that may form or tend to form therein;

The products of combustion and of volatilization pass downwardly through the main stack and take their exit through a series of lateral apertures 7L therein, this down-draft being induced by the chimney stacks or exhaust pipes F1, or by forcing air or gas through the admission pipes c and s, or by both of said expedients. From the apertures 7L, they enter'the condensers F, through the inclined passage ways h, and the condensable metal present (as, for instance, zinc) will collect in the condensers, which l have here shown of the familiar type used in the metallurgy of zinc. In order that the condensed metal may remain in a liquid or molten state in the condensers, so that it may be readily drawn out, at intervals, as it collects, l locate the condensers in surrounding chambers G. The volatile products of combustion including all the non-condensed products of reaction issuing from the open ends of the condensers, on their Way to the chimneys or exhaust pipes E, will occupy these chambers G, thereby maintaining the requisite temperature therein, which will be above the melting point of thecondensed Zinc or other like metal. To withdraw the metal from the condensers, the fire-clay plugs i, y', are temporarily removed, the usual hoe-like scraper is inserted into the condenser and the metal is drawn out through the openmouth of the condenser and is caught in a hand ladle, or the like, as it falls through the aperture from which the plug j has been removed.. One of these hand ladies or collectors is shown at g in Fig. 2. Fireclay plugs 7c, 7L" are likewise provided, so that, when temporarily removed, a suitable bar or tool may be inserted to keep the aperture h open beyond the plug 7e. 'lt will, of course, be understood that, after the temporary removal of these several plugs, they are replaced by new plugs, likewise of lire-clay.

As modifications of the 'furnace shown, ,l

' may employ furnaces of other constructions adapted to carry out the method herein claimed, as, for instance, any of the forms of furnace shown in my co-pending application, Serial No. 295,929, hereinbefore referred to.

As an illustration of the employment of my invention in the metallurgical arts, l will now describe it as applied to the recovery of Zinc from its ores.

If the zinc ore to be treated is blende, it must first be roasted, and, in any event, the zinc ore should contain the Zinc in the form of oxid, in making up the furnace charge, although, it will be understood that waste Zinc in the form of galvanizers dross or the like may be used as a part of the charge, if so desired. The Zinc ore and the like is mixed to furnish the carbon required for the reduction of the zinc oXid, and to also generate, by combustion the necessary heat of re action. The mixture, constituting the furnace charge, is fed through the hopper B into the conveying apparatus, which feeds it continuously into and through the main stack, in an upward direction, the rate of revolution of the conveyers being determined by the progress of the reducing operation in the stack.

As soon as the charge passes the apertures 7L, it meets the hot products of combustion and of re-action, which travel from the stack in a downward direction, and the coke or anthracite coal of the charge becomes ignited. As soon as the charge attains the necessary temperature the coke orcoal commences to reduce the Zinc oXid to metallic Zinc, which, at the high temperature pre vailing, assumes the form of Zinc vapors. rFliese vapors leave the stack, from the apertures 7L, together with the gases of combustion, which are highly reducing, in the lower part of the stack, because of the fact that, on their way downward., they pass through a thick layer of glowing fuel. As the charge ascends still further, its temperature increases and more zinc oxid is reduced to me tallic Zinc. Finally, in the upper part of the stack, where the temperature is highest, the gases of combustion are less strongly reducing, and, at this point, a certain amount of CO2 is present, which has not yet been converted into CO by glowing carbon. The CO2 thus present will temporarily reoxidize a portion of the Zinc liberated, but, as this oXid on its way downward, meets new particles of glowing carbon it will be again reduced and will then remain in the metallic state, for the reason thatv in the mean time, the CO2 with which it has descended in the stack, has itself been reduced by other particles of carbon to CO, which is a strongly reducing gas.

The charge attains its highest temperature at the top of the main stack, so that as it is passing over into the ash stack practically all of the Zinc contained in the charge has been driven out. Whatever remains, in the ash or cinder which passed over into the ash stack, is liberated in the form of zinc oxid the deep bed of glowing carbon below to CO,

as above described. l admit only sufficient air to overcome the resistance offered by the charge 1n the main stack and the ash 1n the 'llO respondingly large volume of CO. These gases of combustion can be utilized for generating power to drive the machinery of the plant, as, for instance, the conveyers, the blower used for producing the air blast, and the like. To increase the reducing effect, l

' may admit either CO or CO2 or both into from an outside producer, or other suitable source, or, if preferred, from the pipe s arranged at the bottom of the ash stack. Any CO2 thus admitted will be converted into CO in passing downwardly through the glowing fuel of the main charge, as hereinbefore described. The inlet pipes referred to may serve for the'admission of any gas containing CO or CO2, such as producer gas or water gas, or any other gas of a reducing character, such as, for instance, ordinary coal or oil gas or, the gas may be derived wholly or in part from the auxiliary producer stack of the furnace. 1 may also, as hereinbefore described, increase the reducing effect by inserting solid or liquid fuel through the inlet pipes m.

The gaseous products of combustion and of re-action, passing through the apertures h, enter the condensers F, wherein the greater part of the zinc is recovered in liquid form. The gas then issues into the interior of the chambers G, in which further portions of the zinc may be recovered as blue powder. From the chambers G, the gases take their exit through the chimneys or exhaust pipes E and any other valuable portions of their metallurgical contents may be recovered in the usual manner, by the aid of filters, fume arresters, bags, or the like, the combustible gases still remaining being ultimately utilizable, as stated for the generation of power for the various purposes of the plant.

Having thus described my invention, what l claim is:

l. The method of treating ore or the like in an internally heated furnace, which consists in feeding the charge containing the ore in an upward direction through the active zone or zones of the furnace and progressively supplying from below fresh portions of the ore charge and supplying a body of air to promote combustion within the charge; substantially as described. i

2. The method of treating ore or the like in an internally heated furnace, which consists in feeding the charge containing the ore in an upward direction through the active zone or zones of the furnace, progressively supplying,

from below, fresh portions of the charge, and causing the air necessary for combustion to traverse the active zone or zones in a downward direction; substantially as described.

3. The method of 'treating ore or the like in an internally heated furnace, which consists in feeding the charge containing the orein an upward direction through the active zone or zones of the furnace, progressively supplying, from below, fresh portions of the charge, causing the air necessary for combustion to traverse the combustion zone in a downward direction, and withdrawing the volatile products of combustion and reaction laterally from the moving charge substantially as described.

4. The method of treating ore or the like in an internally heated furnace, which consists in feeding the charge containing the ore in an upward direction through the active zone or zones of the furnace, progressively supplying, from below, fresh portions of the charge, causing the air necessary for the combustion to traverse the active zone or zones in a downward direction, withdrawing the products of combustion and reaction laterally from the moving charge and condensing out any distilled or vaporized metal contained in said products, at their point of issuance from the charge; substantially as described.

5. The method of treating ore or the like in an internally heated furnace, which consists in feeding the charge containing the ore in an upward direction through the active zone or zones of the furnace, progressively supplying from below, fresh portions of the charge, causing the air necessary for combustion to traverse the active zone or zones in a downward direction, withdrawing the products of combustion andreaction laterally from the moving charge, condensing out any distilled or vaporized metal contained in said products, at their point of issuance from the charge, and maintaining the temperature of the condensed metal above its melting point so as to permit its collection in a liquid state; substantially as described.

6. The method 'of treating ore, or the like, in an internally heated furnace, which consists in feeding the charge containing the ore, in an upward direction, through the active zone or zones of the furnace, progressively supplying, from below, fresh portions of the ore charge, diverting laterally and downlWardly the spent portions or ash of the charge above the active zone or zones, and utilizing the waste heat of said ash by passing the incoming air or other gases through it on its way to the active zone or zones; substantially as described.

7. The method of treating ore, or the like, in an internally heated furnace, which consists in feeding the charge containing the ores, in an upward direction, through the acsired, at such point of diversion; substantive Zone or Zones of the furnace, progresstially as described. 10 ively supplying, from below, 'fresh portions of In testimony whereof I aiiix niy signature, the ore charge, diverting` laterally, above the in presence of tWo Witnesses.

5 active zone or Zones, the spent portions or FRANZ MEYER.

ash oi the charge, and controlling the condi- Witnesses: tions prevailing at the active zone or Zones F. G. HARTMANN,

by adding reducing agents or the like, as de- H. SoHWEiNsBERG. 

